Can you (or anyone, really) show that there were, or were not, any lives saved? That there were people killed is quite easy to show, but showing that there were crashes prevented... that does not even seem provable.
You can't show (least of all on some fanboy Youtube video) that AutoPilot had prevented a crash, compared to a normal person just driving a car. A Tesla crashing into a firetruck -- that you can show.
What you could show would be crash statistics over a significant population of similar cars, in similar conditions, driving on similar roads. These statistics don't seem to show any safety benefit to Tesla, but believers will believe.